Background: For any therapeutic approach, it is important to consider what factors determine its suitability for clients. As cognitive-behavioural therapy (or, CBT), is increasingly being investigated as a therapeutic intervention for adults with intellectual disabilities, this literature review considers the status of empirical evidence concerning factors that determine CBT suitability for this population. Method: Using five electronic databases, searches were conducted to identify relevant empirical papers published between 1997 and 2010. Results: Fifteen studies, of seventeen identified, were reviewed. Studies concerned either factors relating to CBT intervention responsiveness or the ability of participants to complete tasks thought necessary for CBT. Across the reviewed studies, several client and contextual factors of potential importance were identified. The veracity of these findings is considered with reference to study methodological issues. Conclusions: Although a number of potentially important client and contextual factors have been identified in the literature, further investigations are needed to more clearly establish which of these relate to CBT intervention responsiveness.